With Hurricane Irene swirling closer to the tri-state, all New Yorkers in vulnerable areas have been ordered to evacuate with just hours to go before subways, buses and commuter trains begin shutting down.

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Mayor Bloomberg said Consolidated Edison is considering shutting off power in the city's low-lying areas before the storm hits, meaning wide swaths of the city could go dark Saturday night.

"You can plan on the possibility of no power downtown," he said.

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Forecasters say Hurricane Irene could make landfall in New York as a Category 1 hurricane, or slightly weaker. It depends on whether the storm loses steam as it moves up the East Coast.

Irene was bashing North Carolina with winds of 80 mph Saturday morning and is expected to arrive in the tri-state area late Saturday into Sunday.

The city's primary evacuation zone includes Battery Park City, Coney Island, Manhattan Beach, Far Rockaway and Midland Beach and South Beach in Staten Island. See the zone in orange on this map.

For all your hurricane preparedness questions, go here. You can also make sure you're taking all the right steps with this preparedness checklist.

NEW YORK CITY

The unprecedented transit shutdown includes New Jersey Transit and PATH trains and will begin as trains and buses start their final runs, likely taking several hours to complete.

Many New Yorkers in the primary evacuation zone are refusing to leave. "There's no way in hell that we are leaving home," said Pat Jones, of the Rockaways. "This is my home, and I'm staying here and protecting my home. Wouldn't you?"

Public housing buildings in low-lying areas will shut down their elevators on Saturday so that people don't get trapped. Bloomberg said other buildings may do the same.

Some 250,000 people live in the low-lying areas that are under the mandatory evacuation order. Bloomberg said New York has never ordered such an evacuation.

New Yorkers in the primary zone must leave by 5 p.m. Saturday, Bloomberg said.

If winds exceed 40 mph, there will be traffic restrictions on area bridges. If they exceed 60 mph, bridges will be shut down.

All tri-state-area airports will close to arriving flights at noon Saturday, but will remain open for departing flights until further notice.

The mayor also warned that a transit shutdown would take hours to re-start, so there will likely be no mass transit until midday Monday, at the earliest.

The MTA has never before halted its entire system — which carries about 5 million passengers on an average weekday — in advance of a storm, though the system was seriously hobbled by an August 2007 rainstorm that disabled or delayed every one of the city's subway lines. The last planned shutdown of the entire transit system was during a 2005 strike.

The city on Friday ordered all construction work halted for the weekend.

The city is urging residents to stock up on groceries and flashlights and to make preparations for potential evacuations. For instructions on what to do and to find whether you live in a New York City evacuation zone, click here.

The NYPD has stationed row boats at police precincts in flood-prone areas. Emergency Service Unit officers also have small motorized boats that they can deploy in floods.

NEW JERSEY

Nearly all of the New Jersey shore and the entire southern half of the state are under a hurricane warning, and mandatory evacuations are under way in Cape May County, coastal Atlantic County, coastal Monmouth County and Long Beach Island.

Hoboken has also issued a mandatory evacuation order for all ground-floor units.

Hundreds of evacuees have arrived in Trenton at the Sun National Bank Center arena. The state has been busing people there from shore communities.

Officials have called for voluntary evacuations in other areas along the coast.

The southbound Garden State Parkway will be closed Friday at 8 p.m., south of Exit 98.

Gov. Chris Christie said he saw television footage of people trying to squeeze in a bit more beach time on a sunny Friday, and wasn't amused. "Get the hell off the beach in Asbury Park," he said during an afternoon news briefing. "You're done. Do not waste any more time working on your tan."

Tolls are suspended on the Garden State Parkway south of the Raritan River and along the Atlantic City Expressway as motorists try to flee the evacuation zones.

The city's 11 casinos are closing Friday. It's only the third time in the 33-year history of casino gambling in New Jersey that the gambling halls would be closed.

Nassau County is ordering mandatory evacuations for everyone south of Sunrise Highway between Queens and Rockville Centre, and south of Merrick Road from Rockville Centre to the Suffolk border.

Residents in low-lying areas on the North Shore are also under a mandatory evacuation order. In total, about 250,000 people must be out by 5 p.m. Saturday.

In Suffolk, Fire Island, Babylon and Islip are under a mandatory evacuation order, and Brookhaven will begin mandatory evacuations at 8 a.m. Saturday.

Voluntary evacuations are being encouraged in Atlantic Beach, East Atlantic Beach, Lido Beach, Long Beach and Point Lookout.

Suffolk County is asking for voluntary evacuations in all Suffolk coastal areas.

Suffolk County Executive Steve Levy said more mandatory evacuations will begin Saturday, and the areas are still being determined. He said all residents should be prepared to get out. "We have to plan for the real deal here," Levy said. "Start making your plans now so you have adequate time to deal with the situation."

LIPA has called in extra workers from utilities in Pennsylvania to deal with possible power outages.

For Nassau evacuation routes and other emergency planning tools, go here. For Suffolk, start here. Please note, the Suffolk site has been experiencing problems Friday.

CONNECTICUT

Gov. Dannel P. Malloy has also declared a state of emergency.

Connecticut Light & Power, which serves 1.2 million customers, said it was canceling vacations, putting all its personnel on standby and coordinating with sister companies in Massachusetts and New Hampshire to have crews available to restore power.

Days ahead of Irene's expected arrival, marinas pulled boats in from the water, tourists canceled shoreline getaways and Malloy urged residents to make storm preparations.

Malloy urged local governments to clear drainage facilities ahead of the storm, which is projected to approach the state on Sunday. While the track and intensity of the storm remain uncertain, state officials said it could drop 6-10 inches of rain with more than a foot in isolated areas.

Officials said the state does not see a need for any evacuations but that could change.

You can keep an eye on the forecast through our interactive radar, and stay with NBC New York on Twitter @NBCNewYork and Facebook/NBCNewYork.